A MIMO (Multiple Input and Multiple Output) system has become a technique drawing much attention in an LTE (Long Term Evolution) system due to its increased channel capacity. In a multi-user MIMO mode, a beamforming direction is devised by designing suitable weight vectors of transmit antennas and receive antennas, thus multi-user signals can be discriminated and the interference among users can be eliminated.
A beamforming method discriminates users based on their orientations, thus achieving that a plurality of users can multiplex same time and frequency resources, which is more useful for controlling a beam direction in the case of a small antenna interval (0.5λ). A beamforming technique operates mainly by controlling a beam direction, and is applicable to open suburb scenarios. Beamforming can obtain obvious beam energy gain, and can enlarge cell coverage. In the multi-user MIMO mode, the beamforming direction is devised by designing suitable weight vectors of transmit antennas and receive antennas, the specific shape of a beam is controlled, a main lobe can be formed in a desired direction, and a null steering is formed in an interference direction, thus the interference among users is eliminated. However, at present, how to deal with the beamforming among a plurality of users is still under study. Particularly with respect to how to apply the beamforming into a FDD system, there is no efficient solution provided in the related art.